Presentation on theme: "Dr. Hadass Cohen PEST CONTROL IN AGRICULTURE C rop Protection."— Presentation transcript:
Dr. Hadass Cohen PEST CONTROL IN AGRICULTURE C rop Protection
This course provides an holistic view on pest management, emphasizing the integration of different methods for maintaining pests, diseases and weeds below damaging levels, with the goal of minimizing the use of chemical pesticides that disrupt the environment. Course Description
Course Objectives Introduction: A short review on different approaches to pest management Introduction: A short review on different approaches to pest management
2.Integrated Pest Management (IPM),principles. 3. IPM applications: Apple orchard program for the control of: insects, arthropods & diseases. 4. Cotton program for the control of weeds & insects. 5. Greenhouse latest engineering and their impact on crop protection. 6. Natural fertilizers. Course Objectives
The course concludes with a visit in an R&D facility, demonstrating some practices of IPM in fruit & vegetables.
Introduction: A short review on different approaches to pest management Introduction: A short review on different approaches to pest management
Cultural Mechanical Physical Chemical Biological Genetic Engineering of Plants Pest Control Methods
Intensive Farming Intensive farming is an agricultural system that aims to get maximum yield from the available land. Under this technique, food is produced in large quantities with the help of chemical fertilizers and pesticides that are appropriately used to save such agricultural land from pests and crop diseases
Intensive Farming - Advantages Aids in solving the worldwide hunger problems to a great extent, contributes towards meeting the ever-growing demand for food supplies. It is cost effective, common people can afford a balanced and nutritious diet
Intensive Farming - Advantages Have enabled a substantial increase in production. in contrast to many sorts of sustainable agriculture such as organic farming or extensive agriculture
Impacts of Intensive Farming on Soil Soil erosion from farmland threatens the productivity of agricultural fields. The sub soils that remain tend to be: less fertile less absorbent, less able to retain pesticides less able to retain fertilizers less able to retain plant nutrients.
Impacts of Intensive Farming on Water Increasing erosion and poisoning water with agricultural chemicals.
Impacts of Intensive Farming - Example Cucumber growers in the Sharon region, Israel, have been growing the same crop for the last 3 decades. Plant protection problems have aroused: Decline of nutrients in soil Attack of new viruses, diseases & pests Resistance to pesticides
Impacts of Intensive Farming on Livestock Involve very large numbers of animals raised on limited land which require large amounts of food, water and medical inputs, causes: Pollution Various diseases Infections Poor hygiene
Crop Rotation Intercropping Phonological Asynchrony Sanitation Managed Application Resistant Varieties Trap Crops Cultural Control in Intensive Farming
Crop Rotation Intensive grazing affects animal health Crop rotation may contribute to overcome pest attacks Pasture rotation had eliminated cattle fever, in southern U.S., by avoiding the transmission of the disease by cattle ticks, Boophilus annulatus. Example
Intercropping May increase environmental diversity or abundance of natural enemies, such as predator spiders or parasitic wasps Example Inter-planted plants act as a food source or breeding ground for beneficial insects as they search out for pests.
Phonological Asynchrony Altering the time of year for planting or harvesting. Example Sweet corn can escape most injury from corn earworms (Helicoverpa zea) if it is planted in early spring and harvested before larvae mature.
Sanitation Removing crop debris Example Removing crop debris from cotton fields after harvest eliminates overwintering populations of pink bollworms. (Pectinophora gossypiella )
Managed Application Managed application of water or fertilizer can have a big impact on the survival of pest populations. Example Regular rainfall (or overhead irrigation) can significantly reduce infestations of twospotted spider mites (Tetranychus urticae) in tree fruits.
Plant Resistant Varieties S election of plant resistant varieties Exampl e Growing resistant varieties of wheat for reducing severity of wheat stem sawfly
Trap Crops The idea is to lure certain pests away from the target crop onto the trap crops which then need to be removed once they are infected. Example French Marigold protect vegetables from nematodes.
Cultivation Exclusion using screens or barriers Trapping Mechanical Control
Cultivation Example Clean tillage between field rotations, or remove weeds by hand (home gardener, organic grower or researchers), decreases the establishment of new weeds.
Exclusion Exclusion by using screens or barriers Example Banding trees with Tangle foot to control cankerworms.
Trapping (suction devices, collecting machines) Example Mass trapping of tea mosquito bugs with yellow sticky traps loaded with pheromone.
Heat Example Burning surface residues, soil pasteurization. Cold Example Cold storage of potatoes to prevent storage rot. Physical Control
Chemicals – Conventional Pesticides Types of pesticides – With Relation to Habitat Narrow-spectrum /broad-spectrum Targeted organisms -no harm to non-target Kills a variety of organisms in addition to pest
First Generation Pesticides Historically Used Pesticides Inorganic compounds (minerals) –Lead –Mercury –Arsenic Botanicals –Nicotine –Pyrethrum –Rotenone
Second Generation Pesticides, Synthetic Dichloro-diphenyl-trichloroethane(DDT) Synthesized in 1873 Insecticidal properties –Paul Müller, 1939 (Nobel Prize) used to control body lice Widespread use Banned in US in 1972 Currently there are thousands of synthetic pesticide products, made up of more than 1,000 different chemicals and combinations, not as environmentally, persistent as DDT
DDT is a powerful insecticide. It binds to the voltage-gated sodium channel and locks it in the open state. Prolonged influx of sodium ions causes the nerves to fire repeatedly and this causes death of the insect
DDT is Blamed Causing the Decline of the Bald Eagle Population Unfortunately, even though DDT is not immediately toxic to other animals it does have one disadvantage: it is extremely stable—its biological half-life is about eight years. Furthermore, DDT is stored in fatty tissues and its buildup in birds and fish resulted in considerable loss of these species. That, coupled with the evolution of DDT resistant insects, led to a ban of DDT in most countries by the 1970's
Synthetic Insecticides: Modes of Action (1) Organochlorines & Pyrethroids Retards closure of ion channel in CNS, results in repetitive spontaneous nervous discharges. ( DDT, aldrin, dieldrin, chlordane) (fenvalerate, permethrin) Organophosphates & Carbomates * Binds to hydroxyl group to inhibit formation of acetyl- cholinesterase. (Malathion, diazinon, methylparathion)(Carbaryl, carbofuran, methiocarb) * Insect growth regulators (fenoxycarb)
Neonicotinoids Act selectively on insect nicotinic acetylcholine receptors. (imidacloprid, thiacloprid, spinosad ) Biologicals Complex of various modes and sites. (Bt, abamectin, carpo-virus) Semiochemicals (synthetic sex pheromones, attract & kill strategy). Synthetic Insecticides: Modes of Action (2)
Growth & Development Chitin Synthetic Inhibitors Chitin synthesis inhibitors (cyromazine, diflubenzuron) Insect Growth Regulators Ecdison agonist, causing the insect to unable to molt. (tebufenozide, halofenozide) J uvenile hormone mimic, interfering in the insects metamorphoses (hydroprene, methoprene) Synthetic Insecticides: Modes of Action (3)
Metabolic/Energy processes + Botanicals Oxidative phosphorylation disruptor – inhibitor (fenbutatin oxide, cyhexatin, pymetrozine) Horticultural oils Mechanical suffocation by blocking breathing or disruption of cellular membranes Nontoxic attack, feeding barrier (kaolin – repellent) Electron transport inhibitor (rotenone - botanical) Synthetic Insecticides: Modes of Action (4)
Synthetic Insecticides: Advantages Protecting cultivated crops from most pest invasions Cost effective Marking a major advance in crop protection, replacing the inferior pesticides based on metallic salts
Synthetic Insecticides: Disadvantages Ecological and Medical Problems Chemicals lace the food with residues Estimation: Only 0.1% of the chemicals used in crop protection reach the target pest 99.9% of chemicals, enter the environment to cause hazards to non- target organisms including humans Health risks associated with conventional pesticide residues in foods are well- established and subject to intensive regulatory efforts aimed at reducing exposure
. Global demand for fertilizer nutrients (a) & pesticide active ingredients (b),
. Global demand shares by region for fertilizer nutrients (a) & pesticide active ingredients (b), 2010
There are currently more than 1,600 pesticides available and about 4.4 million tons used annually, at a cost of more than $20 billion. The United States accounts for more than 25 percent of this market. Global Use of Pesticides
Types of Natural Enemies Parasitoids Pathogens Predators Weed Feeders
Parasitoids Major characteristics of insect parasitoids: Specialized in their choice of host Smaller than host only the female searches for host Different parasitoid species can attack different life stages of host Eggs or larvae are usually laid in, on, or near host Immature remain on or in host; adults are free-living, mobile, and may be predaceous Immature almost always kill host
Entomoparasitoids Example Trichogramma nubilale wasp Trichogramma lay their eggs inside the eggs of corn borers and other moths. When the Trichogramma hatch, they begin to eat the developing caterpillar inside the egg.
Pathogens Major characteristics of insect pathogens: Kill or reduce reproduction, slow growth, or shorten the life of pests. Usually specific to target species or to specific life stages. Effectiveness may depend on environmental conditions or host abundance. Degree of control may be unpredictable. Relatively slow acting (several days) to provide adequate control.
Entoemopathogen Example Verticillium lecanii produces a cyclodepsipeptide toxin called bassianolide, which has been shown to kill silkworm. The fungus produces other insecticidal toxins such as dipicolinic acid. The activity of V. lecanii depends on the strain of the fungus. V. lecanii strains with small spores infect aphids, whereas, fungal strains with large spores infect whiteflies.
Predators Major characteristics of arthropod predators: Adults and immature are often generalists rather than specialists Generally are larger than their prey Kill or consume many prey Attack immature and adult prey
Predatory beetles Example Cryptolaemus montrouzieri feeds on mealy bug Beetles lay eggs directly into mealybug egg sacs. Larvae grow to 13 mm long and are covered in waxy filaments closely resemble their mealybug prey. All stages are predatory on mealybugs. The young predacious larva sucks out the body contents of its mealybug prey, passing through four instars before pupating on nearby. supports.
Weed-Feeding Natural Enemies Insects - can control weeds by feeding on seeds, flowers, leaves, stems, roots, or combinations of these, or by transmitting plant pathogens, which will infect plants. Other natural enemies of weeds include plant pathogens: nematodes,vertebrates, fungi
Weed-Feeding Fungi Example The fungus Colletotrichum gloeosporioides f. sp. Aeschynomene, causes an anthracnose on Aeschynomene virginica and has been used as a biological control agent to control this weed in the U.S. Aeschynomene is known as a noxious weed which infests rice and soybean fields in North America.
1. It poses little threat to non-target organisms 2. Once established, biological control agents are self perpetuating and can spread on their own, while other control methods require action or inputs periodically 3. The environmental impact is generally low 4. The pest is unable (or very slow) to develop a resistance. Biological Control, Advantages
1. Control is slow. 2. Density dependent. 3. It will not exterminate the pest. 4. It is often unpredictable. 5. It is difficult and expensive to develop and supply. 6. It requires expert supervision. Biolagical Control, Disadvantages
Plant disease induced resistance Plant resistance to insects (genetic engineering) Plant resistance and tolerance to nematodes Plant Resistance
Plant Disease Resistance Plant disease resistance derives both from pre-formed defenses and from infection-induced responses mediated by the plant immune system
Plant Resistance to Nematodes Resistance to some species of Meloidogyne in beans (large lima), cowpeas, sweet potatoes, and tomatoes are the only cases where plant resistance is currently used as a nematode management tactic. Resistant cultivars, especially of sweet potatoes and tomatoes, have been used mostly in conjunction with a preplant fumigation treatment.
Most genetically modified organisms (GMOs) are altered to be herbicide-resistant (over 70% of all GMOs), others include insect - resistant. Example Transgenic Bt corn, cotton potato, tomato and rice are grown instead of Bt spray usage. The most common grown one is Bt cotton. Genetic Engineering of Plants
Economic benefits - crop yields are saved from loss to insect pests and money is saved by not applying insecticides that would have been applied to susceptible varieties. Ecological and environmental benefits - increases in species diversity in the agro-ecosystem, in part because of reduced use of insecticides, far less polluted and detrimental to natural resources. Insect-Resistant - Advantages
Genetic Engineering of Pest SIT – Sterile Insect Technique Example The sterile insect technique (SIT) is used to control fruit fly pests of economic significance, throughout the world